Enclosed disconnect switch



Nov. 21, 1967 Filed Oct. 28, 1966 G. R. MCCLOUD 3,354,272

CLOSED DISCONNECT SWITCH 2 Sheets-Shget 1 INVENTOR. george R. We Cloud Nov. 21, 1967 G. R. MCCLOUD ENCLOSED DISCONNECT SWITCH 2 Sheets-Sheet Filed Oct. 28, 1966 INVENTOR. 2:76 R. d fcCZoz/d jZM W/Qh/QI fittorng/ United States Patent 3,354,272 ENCLOSED DISCONNECT SWITCH George R. McCloud, South Milwaukee, Wis., assignor to McGraw-Edison Company, Milwaukee, Wis., a corporation of Delaware Filed Oct. 28, 1966, Ser. N0.590,300 1 Claim. (Cl. 200-48) ABSTRACT OF THE DISGLOSURE A housed switch comprising a hollow insulating housing having a closure door pivotally mounted at the upper end of the housing by a hinge pin, and a low friction latch surface integrally formed on the upper end of the housing and including first and second shoulder portions and an interconnecting generally arcuate surface having its center of curvature substantially at the axis of the hinge pin. A slotted detent latch member is mounted on the hinge pin and is spring urged into engagement with the shoulder portions to releasably hold the door in its open or closed positions and is slideable between positions on the low friction arcuate surface upon application of a sufiicient force to the lower end of the door.

Background of the invention This invention relates to disconnect switches and, more particularly, to the door latch assembly for a housed disconnect switch.

Disconnect switches are commonly employed for interconnecting and sectionalizing various portions of an electric distribution system. When used in outdoor applications, it is also common to enclose such switches in a porcelain housing which provides a large leakage distance between terminals and protects the operating parts from rain and sleet. These housings are generally provided with a pivotally mounted door which is opened when the switch blade is being pivoted and which is reclosed when the blade is in an open position to isolate the switch blade from the switch contacts and to give a visual indication that the switch is open. Housings of this type generally include a first latch structure for holding the door in its closed position and a second latch structure for holding the door in an open position so that the switch blade may be pivoted.

It is an object of the invention to provide a new and improved latch structure for the door of a housed protective device. 7

A further object of the invention is to provide a single latch structure for holding the door of a housed protective device in each of its open and closed positions.

Brief description of the drawings FIG. 1 is a side elevational view, partly in section, of the housed switch according to the instant invention;

FIG. 2 is a view taken along lines 22 of FIG. 1;

FIG. 3 is a view taken along lines 33 of FIG. 1;

FIG. 4 is a fragmentary view showing the latch structure according to the instant invention;

FIG. 5 is a view taken along lines 55 of FIG. 4; and

FIG. 6 is a fragmentary view showing the latch assembly of FIG. 1 in its alternate position.

Description of the preferred embodiment In general terms, the invention comprises a hollow insulating housing for enclosing a switch, a closure door having a first latch means disposed adjacent its upper end and a second latch means disposed on the upper end of the housing, wherein one of the latch means has first and second spaced engageable means and the other latch means is resiliently mounted for movement into ice latching engagement with the first engageable means for releasably latching the door in a closed position and with the second engageable means for releasably latching the door in an open position.

Referring again to FIG. 1, the housed switch assembly, designated by the general reference numeral 10, includes a hollow housing 11 having a front opening 12 which is provided with a closure door 13. The housing 11 and the door 13 may be formed of any suitable insulating material, which has been molded to the desired shape. A bracket 14 is provided at the rear of the housing 11 for securing the assembly to a pole or other support structure.

The door 13 is shown in FIGS. 1 and 2 to be pivotally mounted at its upper end to the housing 11 by means of a hinge pin or trunnion 16 which passes through aligned openings 17 formed in a pair of spaced apart eye portions 18 integrally formed in said upper end. The trunnion 16 also passes through a bore 19 formed in a central boss 20 which is integral with the upper end of the door 13 and disposed between the eye portions 18. In addition, the ends of the trunnion 16 are secured in metal insert members 21 of molded insulation, which are disposed in suitable apertures forrned in the upper end of housing 11.

A switch assembly 22 is disposed within the housing 11 and includes upper and lower fixed terminals 23 and 24, respectively, which are adapted to be bridged by a pair of switch blades 26. Each of the terminals 23 and 24 is mounted on a bracket member 27 which is suitably secured within the housing 11 and each includes a conductor clamp 28. The terminals 23 and 24 are in circuit with the distribution system by conductors (not shown) which extend through apertures 29 formed in the side walls of the housing 11 and adjacent terminal clamps 28 for engagement therewith.

Each of the terminals 23 and 24 is also provided with a generally flat fixed contact member 30 which is constructed and arranged to be engaged by the switch blades 26 when the latter are in their closed position shown by full lines in FIG. 1. The switch blades 26 may be joined in a parallel relation by a pair of pins 31 and 32 and a hinge pin 33.

As shown in FIGS. 1 and 3, the hinge pin 33 also extends through suitably aligned openings 34 in a channel shaped hinge member 35 which is fixably secured adjacent the lower end of the housing 11. In this manner the switch blades 26 are pivotally mounted for movement between a closed position shown by full lines in FIG. 1 to an open position shown by phantom lines. It can also be seen that the hinge member 35 is insulated from each of the terminals 23 and 24 so that the switch blade 26 will also be insulated therefrom when it is in open position.

A door latch assembly 37, according to the instant invention, is provided at the upper end of the door 13 for releasably holding the door in its closed position shown in FIGS. 1 and 4 and in its open position shown in FIG. 6. The assembly 37 includes a latch member or detent 38 which is bent into an inverted generally U-shape form to provide a pair of downwardly extending legs 40 and a central bridging portion 41. The legs 40 straddle the boss 20 and each has a slot 42 formed therein for receiving the trunnion 16. The central bridging portion 41 is formed with front and rear sloping planar portions 47 and 48 which form an apex 49.

A recess 43 is formed in the upper surface of the boss 20 for receiving the lower end of a coil spring 45. The upper end of spring engages the underside of the apex 49 of the central bridging portion 41 through a centering pin 46 whereby the member 38 is urged upwardly relative to the boss 20.

The underside 51 of the roof of the housing 11 is provided with an integrally formed latching surface 50 opposite the latch member 38. The latching surface 56 includes a pair of spaced shoulder portions 52 and 53 which extend in a direction generally parallel to the trunnion 16 and are disposed generally equidistantly therefrom. A concave arcuate surface 54 is substantially coaxial with the trunnion 16 and extends inwardly of the housing 11 for interconnecting the shoulder portions 52 and 53.

When the door 13 is in its closed position, the front planar portion 47 of the latching member 38 is urged into engagement with the shoulder 52 to resist counterclockwise rotation of the door 13 to its open position. In this manner the door 13 is releasably latched at its closed position.

Rotation of the door 13 may be accomplished by engaging a hookstick (not shown) in an extension 58 on the lower end of the door 13 and pivoting the latter about trunnion 16. As the door 13 pivots, the latch member 38 will be force downwardly toward the boss and against the spring 45 as the result of the cam action between the planar portion 47 and the shoulder 52. After the door has pivoted through a small angle, the apex 49 of the member 38 will move onto the arcuate surface 54 so that the latch 37 will offer little further resistance to rotation of the door 13. When the door has been pivoted to substantially its horizontal position, the surface will snap against the shoulder 53. In this manner the weight of the door will be supported, and the door will be held in its open position.

Rotation of the switch blade 26, after the door 13 has been pivoted to its open position, is accomplished by a lever tit) which is pivotally mounted intermediate its ends about the in 32. The member 60 has a pull ring 62 formexl at its outer end while its inner end 63 is engageable with a stationary pryout block 65 integral with the terminal 24. When a hookstick (not shown) is engaged in the pull ring 62, the member 60 will be rotated through a slight clockwise angle until the end 63 engages the block 65 wherein further rotation of member 60 will force the switch blades out of engagement with the stationary contacts 30. The switch blades 26 are then rotated to their phantom position in FIG. 1 wherein they extend downwardly through a slot 66 formed in the lower end of the housing 11. I I

The door 13 may then be closed by engaging the extension 58 with the hookstick and pulling the latter downwardly which forces the latch member 38 to move toward the right as viewed in FIG. 5 and out of engagement with the shoulder 53 as a result of the cam action therebetween. Once the apex 49 moves onto the arcuate surface 54 the latch assembly 37 will offer little further resistance to the closing of the door 13. When the door 13 has been returned to its closed position shown in FIG. 1, the spring will snap the latch member 37 upwardly until the front sloping portion 47 engages the shoulder 52 wherein the door will again be latched in its closed position.

The door 11 will then be in its position shown by full lines in FIG. 1 while the switch blades 26 will be hanging out the bottom thereof through the slot 66. This will insulate the switch blades 26 from the terminals 23 and 24 and in addition give the linemen a visual indication that the switch is open.

While only a single embodiment of the instant invention has been shown and described, other modifications thereof will become apparent to those skilled in the art once the invention is known. For this reason it is not intended to limit the invention to the foregoing description but only by thescope of the appended claim.

I claim:

A housed switch comprising a hollow insulating housing having a front opening, a closure door, hinge pin means engaging the upper end of said door and said housing for pivotally mounting said door to said housing, first and second terminal means disposed within said housing, switch blade means pivotally mounted on said housing for movement between a closed position wherein said terminals are bridged and an open position wherein said switch blade is isolated from said terminals, a latch surface integrally formed on the upper end of said housing and comprising first and second shoulder portions formed on said housing and an interconnecting generally arcuate surface having its center of curvature substantially at the axis of -said hinge pin means, a metallic detent latch member having elongate slot means for engaging said hinge pin means, spring means disposed between said latch member and said door and acting in the direction of said slot means to urge .said member away from said door and into engagement with said latch surface, said latch member being resiliently engageable with a first one of said shoulder portions when said door is in a closed position to resist rotation of said door toward its open position and with the other one of said shoulder portions when said door is in an open position to support the weight of said door and resist rotation of said door toward its closed position, said latch member being movable out of engagement with said shoulder portions and onto said arcuate surface for sliding movement to the other of its shoulder portions upon the application of sufficient force to the lower end of said door, said arcuate surface and on said shoulder portions providing a relatively low friction surface with respect to said metallic latch member.

References Cited UNITED STATES PATENTS 2,203,350 6/1940 Froland 200-462 ROBERT S. MACON, Primary Examiner. ROBERT K. SCHAFER, Examiner. H. HOHAUSER, Assistant Examiner. 

